The proposed research is focused on increasing our understanding of the genetic causes of different types of muscular dystrophy. Goals of the research include the identification of causative genes, definition of the range of gene mutations, and the histological and clinical consequences of the gene/protein defects. A strength of the experimental approach is access to a large tissue bank of frozen muscle biopsies from patients. The availability of tissue within defined single gene defects allows comparative mRNA profiling, leading to disease-specific modeling of molecular pathophysiology. The proposed research leverages emerging DNA sequencing technologies to improve the diagnostics of the muscular dystrophies. Aim 1 will develop emulsion PCR to separately amplify 841 exons corresponding to known muscular dystrophy genes, followed by highly parallel nextgen sequencing to identify causative gene mutations. Aim 2 will take the mutation-positive biopsies identified in Aim 1, and conduct mRNA profiling to define disease-specific networks driving the muscle weakness in each gene-defined group. In Aim 3, those patients testing negative for mutations in all 841 exons will be studied by whole-genome sequencing using Illumina and/or Pacific Biosciences methods. We anticipate the identification of multiple new genes causing muscular dystrophy, and this will inform diagnosis, enable experimental therapeutics, and increase knowledge of molecular pathogenesis. Integrated into these laboratory-based human research studies is design and implementation of novel bioinformatics and biostatistical approaches to analyses of genome-wide datasets, though collaboration with Dr. Yue Wang's group at Virginia Polytechnical University. PUBLIC HEALTH RELEVANCE: The proposed research develops new methods for enabling molecular diagnosis of the many types of muscular dystrophy. The proposed research will also identify novel genetic causes of muscular dystrophy, and increase the understanding of the molecular events leading to muscle weakness and disability.